1. Field of the Invention
The present invention relates generally to a band loading device for a packing machine and more particularly to a band loading device which is capable of directly inserting a band into a pair of pre-feed rollers, which is positioned adjacent to an inlet of a pool box, from a band reel provided in a packing machine.
2. Discussion of the Background
Generally, a band guide arch, a sealer unit, a band forward-reverse unit and pool box of a packing machine are arranged in the same plane. An inlet of the pool box and a pair of pre-feed rollers for supplying a band into the pool box are also arranged in the plane of these elements.
A band reel which holds the band and supplies the band to the packing machine is preferably accommodated in the packing machine for safety and to save space. However, it is preferable not to decrease the capacity of the pool box by the band reel. Thus, the band reel is generally arranged at one side of the pool box in the packing machine. That is, the band reel is usually arranged in front of the pool box or behind the pool box in the packing machine.
With this arrangement, however, the band must be twisted at the pre-feed rollers since the band path from the band reel to the pool box is not in the same vertical surface. Thus, the twist of the band should be corrected. Japanese Patent Publication No. Hei 1-52242 discloses one solution for re-twisting the band. That is, as shown in FIG. 4 of Japanese Patent Publication No. Hei 1-52242, a band guide structure is provided in the packing machine. The band guide structure comprises a relay roller rotatably attached on a fixed stand below the band reel and two rollers for turning the direction of the band above the relay roller. The band pulled out from the band reel is relayed by the relay roller. Then, the band is wound by the two rollers in reverse U-shape, so that the twist of the band is corrected at the pre-feed rollers disposed adjacent to the bottom of the pool box. The wound form of the band is also changed.
However, the packing machine disclosed in Japanese Patent Publication No. Hei 1-52242 has some disadvantages. That is, the pre-feed rollers are positioned adjacent to the bottom of the pool box. Thus, the inserting operation of the band into a nip of the pre-feed rollers is not easily executed. The band guide structure can not be formed compactly. Thus, the band guide structure makes the packing machine large. It is not easy to set the band in the band guide structure because the band must be twisted between two rollers, so this operation is not easily executed. High skill is necessary to set the band. Especially, trouble will occur during the packing operation if the band is not correctly set. In this case, the packing operation will be decreased in efficiency.